This invention relates to a vertical tube water heater.
A vertical tube water heater is known from GB-A-2 145 803 which comprises a water tank, a plurality of vertical tubes located within the tank, one end of each of the tubes being in communication with a combustion chamber located at the bottom of the tank and in which are provided burners, and the other end of each tube is in communication with a chamber located at the upper end of the tank and which is in communication with an exhaust duct. When such a known water heater is operated at low temperature settings, condensation is produced in the vertical tubes and the condensate falls by gravity into the combustion chamber and can extinguish the pilot light of the burner or even the burner itself. Therefore such vertical tube water heaters can not be operated at low temperature settings.